The present invention relates to a pharmaceutical preparation containing as the active substance nateglinide which is known as a hypoglycemic agent.
It is known (as disclosed in Japanese Patent Examined Publication (JP Kokoku) No. 4-15221) that nateglinide (chemical name: N-(trans-4-isopropylcyclohexanecarbonyl)-D-phenylalanine, which will be hereinafter referred to as “nateglinide”) shows excellent hypoglycemic action when orally administrated and is useful as an agent for the treatment of diabetes.
Nateglinide has the excellent properties of controlling postprandial hyperglycemia, and tablets containing 30, 60, 90, 120 or 180 mg of nateglinide per tablet are clinically used in practice. The tablets containing 60, 90, 120 or 180 mg of nateglinide per tablet are advantageous in that a relatively large amount of active substance can be ingested in a single administration. However, with respect to the current pharmaceutical preparations containing an optimum dose (90 mg) of nateglinide, for example, in the form of concave shaped tablet (i.e., round-shaped tablet), 25 mass % of nateglinide and 30 mass % of hydroxypropyl cellulose with a low substitution degree as a disintegrant are contained based on the total mass of the preparation, and the tablet is designed to have a diameter of about 10.1 mm, a thickness of about 5.2 mm and a mass of 366 mg. In light of this, there is a need for a smaller-sized nateglinide-containing pharmaceutical preparation that is easier to take (for example, refer to WO98/22105, WO01/21159, WO01/47557, WO02/34254 and WO02/40010).